[1.6.4] A Survivor's Handbook: Dealing with Hardmode Gregtech Lithuex Feb 21st 2014 Hey, how do you know when you're in an extreme hills biome? Do they start/end at a certain height? I have BoP so I dunno if that's screwing with it, but I can never find them in normal games, either. I've googled but that's given scant information.